1. Field of the Invention
This invention relates generally to an automatic transmission, in which a clutch module contains clutch servo pistons and a pump support contains brake servo pistons.
2. Description of the Prior Art
In the kinematic arrangement of an automatic transmission, certain control elements, such as hydraulically-actuated clutches, have no fixed connection to any other transmission lever component.
In such cases, a need exists for a technique that simplifies the feed circuit to those clutches, i.e. pressure feeds for each clutch-apply circuit and respective feeds to balance volumes.
In a hydraulically-actuated automatic transmission for a motor vehicle, transmission brakes produce high drag losses, which adversely affect fuel economy.
When the brake's separator plates are splined directly to the transmission case, automatic transmission fluid in the case is difficult to evacuate, which leads to high drag. When the brake's separator plates are splined directly to the transmission case, installation of the separator plates and friction plates must be completed as a final assembly, instead of as a subassembly, which is preferred.
Forming spline teeth in the transmission case that engage spline teeth on the brake's separator plates can be costly to machine and produces excessive, unwanted scrap.